Using The Herbicide Classification Chart Travis Legleiter Weed

Using The Herbicide Classification Chart Travis Legleiter Weed Science Program Specialist Purdue University

• Classification Chart is a redesign of former Herbicide MOA chart • Part of the “Take Action” effort • Access to chart and other resources: http: //takeactiononweeds. com/

What Causes Herbicide Resistance? • Selection Pressure – The repetitive use of a single mode of action over time under non-ideal conditions.

Mode of Action vs. Site of Action • Terms often interchanged or confused • Mode of Action: The effect of the herbicide on plant growth and eventual death at effective doses. • Site of Action: The enzyme site or pathway that the herbicide binds or inhibits to create the plant growth effects. • Sites of action are subsets of modes of action

Some Modes of Action have one site of action Other Modes of Action have multiple sites of action

Site of Action Group #’s • Each unique site of action given a unique number • Group #’s are easier to use and recognize than scientific site of action names • These group #’s are included on many herbicide labels as well.

Chart Layout: Publication is split down the middle into two Charts:

By Mode of Action: Trade name products and their respective active ingredients

By Mode of Action: Trade name products and their respective active ingredients Grouped By Chemical Family

By Mode of Action: Trade name products and their respective active ingredients Grouped By Chemical Family Grouped By Site of Action

By Mode of Action: Trade name products and their respective active ingredients Grouped By Chemical Family Grouped By Site of Action Grouped By Mode of Action

By Mode of Action: Trade name products and their respective active ingredients Grouped By Chemical Family Grouped By Site of Action Grouped By Mode of Action Chart includes: Number of resistant weed species for each site of action

By Mode of Action: Trade name products and their respective active ingredients Grouped By Chemical Family Grouped By Site of Action Grouped By Mode of Action Chart includes: Number of resistant weed species for each site of action And Most Importantly Group Number and an associated color for each Site of Action

Example: Callisto

Example: Callisto Active Ingredient: mesotrione

Example: Callisto Active Ingredient: mesotrione Chemical Family: Triketone

Example: Callisto Active Ingredient: mesotrione Chemical Family: Triketone Site of Action: HPPD Inhibitor

Example: Callisto Active Ingredient: mesotrione Chemical Family: Triketone Site of Action: HPPD Inhibitor Mode of Action: Pigment Inhibitor

Example: Callisto Active Ingredient: mesotrione Chemical Family: Triketone Site of Action: HPPD Inhibitor Mode of Action: Pigment Inhibitor Number of Resistant Weed Species: 2

Example: Callisto Active Ingredient: mesotrione Chemical Family: Triketone Site of Action: HPPD Inhibitor Mode of Action: Pigment Inhibitor Number of Resistant Weed Species: 2 & Finally Herbicide Group #: 27

By Premix:

By Premix: Premix names listed in alphabetical order

By Premix: Premixes listed in Alphabetical order Includes: -Active ingredients

By Premix: Premixes listed in Alphabetical order Includes: -Active ingredients -Trade names of products w/ single active

By Premix: Premixes listed in Alphabetical order Includes: -Active ingredients -Trade names of products w/ single active -Site of Action Group Numbers and corresponding color coding.

By Premix: Premixes listed in Alphabetical order Includes: -Active ingredients -Trade names of products w/ single active -Site of Action Group Numbers and corresponding color coding. Example: Lexar EZ contains actives: -mesotione (Callisto), smetolachlor(Dual II Magnum), & atrazine(Aatrex)

By Premix: Premixes listed in Alphabetical order Includes: -Active ingredients -Trade names of products w/ single active -Site of Action Group Numbers and corresponding color coding. Example: Lexar EZ contains actives: -mesotione (Callisto), smetolachlor(Dual II Magnum), & atrazine(Aatrex) Those actives are in the site of action groups: -27, 15, & 5

By Premix: Remember Callisto from the “By Mode of Premixes listed in Alphabetical Action” order Chart. You can link to that chart using the color coding (Blue) and group number (27). Includes: -Active ingredients -Trade names of products w/ single active -Site of Action Group Numbers and corresponding color coding. Example: Lexar EZ contains actives: -mesotione (Callisto), smetolachlor(Dual II Magnum), & atrazine(Aatrex) Those actives are in the site of action Groups: -27, 15, & 5

Outline Herbicide Programs • Use chart to outline site of action rotation • Find products on chart and write down site of action group # • What to look for: -# of site of action used -# of effective sites of action used -Selection pressure placed on a site of action (used more than 2 x)

Herbicide Classification Waterhemp (ALS + glyphosate resistant) Timing Herbicide Early Post Extreme Late Post Flexstar GT SOA Active Ingredient(s) Group

Herbicide Classification Waterhemp (ALS + glyphosate resistant) Timing Herbicide Early Post Extreme Late Post Flexstar GT SOA Active Ingredient(s) Group imazethapyr 2 glyphosate 9

Herbicide Classification Waterhemp (ALS + glyphosate resistant) Timing Herbicide Early Post Extreme Late Post Flexstar GT SOA Active Ingredient(s) Group imazethapyr 2 glyphosate 9 fomesafen 14 glyphosate 9

Herbicide Classification Waterhemp (ALS + glyphosate resistant) Timing Herbicide Early Post Extreme Late Post Flexstar GT SOA Active Ingredient(s) Group imazethapyr 2 glyphosate 9 fomesafen 14 glyphosate 9 Effective Sites of Action!

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup 2, 4 -D Burndown Envive Early Post Prefix Late Post Cobra

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 2, 4 -D Burndown Envive Early Post Prefix Late Post Cobra 9

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 9 2, 4 -D 4 Burndown Envive Early Post Prefix Late Post Cobra 2, 4 -D

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 9 2, 4 -D 4 chlorimuron 2 thifensulfuron 2 flumioxazin 14 Burndown Envive Early Post Prefix Late Post Cobra

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 9 2, 4 -D 4 chlorimuron 2 thifensulfuron 2 flumioxazin 14 s-metolachlor 15 fomesafen 14 Burndown Envive Early Post Prefix Late Post Cobra

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 9 2, 4 -D 4 chlorimuron 2 thifensulfuron 2 flumioxazin 14 s-metolachlor 15 fomesafen 14 lactofen 14 Burndown Envive Early Post Prefix Late Post Cobra

Herbicide Classification Palmer Amaranth (ALS + glyphosate resistant) Timing SOA Herbicide Active Ingredient(s) Group Roundup glyphosate 9 2, 4 -D 4 chlorimuron 2 thifensulfuron 2 flumioxazin 14 s-metolachlor 15 fomesafen 14 lactofen 14 Burndown Envive Early Post Prefix Late Post Cobra Effective Sites of Action!

Your Turn! -Write out your soybean program and site of action group numbers -How many Effective Sites of Action do you have? -Write out your programs for a 2 year corn and soybean rotation

Tools For The Battle Against Weeds Purdue Weed Science Webpage: Purdue Weed Science Facebook: https: //ag. purdue. edu/btny/weedscience http: //www. facebook. com/purdue. weedscience Travis Legleiter: Dr. Bill Johnson tlegleit@purdue. edu wgj@purdue. edu (765) 496 -2121 (765) 494 -4656